Trigger mechanism for machine guns



TRGGER MECHANISM FUR MCHNE GUNS William R. luehdorn,

Hartford, Conn., and

Forrest K. Howard, East Falls Church, Va.

Application January 16, 1935, Serial No. 2,028

l. Claim.

(Granted under the act of March 3, 1883, as amended April 3G, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to us of any royalty thereon.

The subject ci this invention is a trigger mechanism for machine guns.

Machine guns mounted on aircraft and adapted to re between 'the blades of the propeller are operated by means of a trigger motor attached to the exterior of the gun casing and synchronized With the motor of the aircraft. The same type of gun is also mounted on other parts or" the aircraft where synchronized firing is not required and it is also employed in tanks and armored cars. In these instances the gun is manually operated either directly or through remote control.

The purpose or" this invention is to provide a hand trigger mechanism which may be readily interchanged with a right or lett trigger motor Without altering the standard equipment of the gun or interfering with its operative parts and which utilizes the attaching means of the trigger motor.

A further object is to provide a simple trigger which may be actuated when the gun equipped with the trigger `is mounted for recoil and counterrecoil movement,

To these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claim forming a part oi this specication.

A practical embodiment of the invention is illustrated in the accompanying drawing, Where- Fig. l is a view in side elevation of a machine gun equipped with the improved trigger.

Fig. 2 is a transverse sectional view through the breech casing and showing the trigger in cocked position.

Fig. 3 is a similar View with the trigger held in the firing position by a remotely controlled mechanism.

Fig. 4 is a sectional view on the line t-l-l of Fig. 3, and

Fig. 5 is a perspective view of the trigger.

Referring to the drawing by characters of reference, there is shown a machine gun of the Browning type whose breech casing consists of spaced side plates 5 5 between which the usual breech bolt E is reciprocally mounted. The bolt has a sear 'l for releasably holding a firing pin (not shown) and is moved by a transversely disposed sear slide 8 which is of the type employed in connection with the trigger motors of synchronized guns.

The side plates Si are each formed with a pair of apertures .ii-i8 for mounting a trigger motor but in the present instance they are employed to mount a plate H of a hand trigger mechanism by means of the conventional front cleat l2 and rear cleat i3 which is associated with a bolt l5 as is Well understood in the art.

The plate li is formed with a groove i5 for receiving a trigger E5 which is pivotally mounted at its front end on a pin il carried by the plate. The trigger is normally held in the cocked position shown in Fig. 2 by means of a spring I8 seated in a recess IS in the plate and in a recess 2i) in the trigger. Outward movement of the trigger is limited by the engagement of its toe 2! with the front Wall 22 of the groove i5 and inward movement is limited by the oor 23 of the groove.

A lug 23 on the inner side oi the trigger eX- tends through an aperture 25 in the plate ii in position to engage the sear slide 8 when the breech bolt is in battery. The rear iaee of the lug is beveled to provide a cam surface 26 which serves, in continuous ring, to actuate the sear slide as the breech bolt approaches the in battery position.

The trigger is actuated by direct manual engagement or by remote control as shown in Fig. 3. In the latter instance a plunger 2l is slidably mounted in a bracket attached to the gun cradle de. The plunger is retracted by means of a cable 39 against the action oi a spring 3| which is conned between the bracket and a pin Et on the plunger'. rThe front end of the plunger is formed with a cam surface 33 for engaging a cam surface it on the iront face of a lug 35 which is provided on the outer side of the trigger. This arrangement functions to press the trigger even when the trigger is longitudinally displaced as when the machine gun is mounted on a recoiling cradle.

We claim:

1n a machine gun having a breech casing, a plate attached to the casing and formed with a groove on its outer side, a trigger lever pivotally mounted at its front end in the plate and disposed in the groove of the plate, the front end of the lever engageable with the plate to limit its movement to cocked position, a spring between the plate and lever and normally holding the lever in cocked position, and a sear actuating lug on the inner side of the lever and in rear of the pivot of said lever, said lug extending through the plate and into the gun.

WLLIAM R. BLUEI-IDORN. FOR/REST K. HOWARD. 

